Both are usually non-musicians (or lapsed ones).
Both declare what's "cool" to the non-knowing proles, often in a condescending way.
Both are always on the hunt for the "relevant", the "next big thing" without actually creating it by themselves, or without any loyalty to it.

Popcultural parasites.

Among the music journalists there are exceptions - the blissblogger one of them - who are genuinly interested.

But then, as pop culture evaporates continuously, they (the smug ones) are less and less "relevant" themselves.

One quintessential hipster move is to invest in the gourmet, upmarket version.
You see this with gentrified burgers and fried chicken, you see it with hand stitched japanese hoodies and the whole fashion end of 'streetwear' and of course you see it in post dubstep.